In reply to Hans:
Process varies hugely for me. At one end of the spectrum, researching a route in guides / books / maps / web then getting local conditions and weather info and going for it. At the other end I might pass a route think 'that looks in good nick' and give it a go. Sometimes it is the look of the route that inspires me, sometimes it is that a route requires a step up in terms of my personal skills, fitness, commitment and performance.
Usually I go to an area with lots of possible routes in mind, always having several options to hand. For example longer / higher / harder committing routes; shorter hard or easy routes that can be snatched in a short weather window, mid mountain long rock routes, valley cragging options and, if all else fails , be prepared to move. Route choice depends on conditions of the routes, how fit and acclimatised I am, how fit and acclimatised my partner / partners are, what grade or type of route we want to climb ( tiger or mouse day ), weather forecast and how long we have.
Rather than sitting around waiting for a dream or planned route to come into condition I prefer to climb almost every day if I can. For example:
Three years ago I was in Chamonix with a partner on his second alpine season. Half way through the trip we had done some routes around 3,500 metres and were reasonably fit and acclimatised. High routes were suffering from strong winds, wind slab, fresh snowfall. So we went up the Aiguilles Rouges and did the Voie Ravanal, about 16 pitches of bolt protected rock climbing to a nice rocky peak. Descent involved some easy moving together ground which was a useful experience for him. Two days more mid mountain cragging later we heard that conditions on the Tacul North Face were now stable but the forecast was for one good day of weather to be followed by more wind and snow high up. So we got the first telepherique in the morning and did the Grisolle route on the Tacul - 8 or so snow and mixed pitches followed by moving together to the summit. The next day the weather was poor but we managed to snatch some valley cragging routes. Forecast looked poor for the next few days so we went to Switzerland and did some routes there.
So for me there is not so much a step by step linear process but a constant bearing in mind of a whole variety of factors - this sometimes even includes 'gut feeling'.
Hope these wandering thoughts help...